Liquid Crystal Display (LCD for short) has been widely used in electronic products such as tablet PCs, TVs or mobile phones for its advantages of low radiation, small size and low power consumption. A display screen of the LCD is provided with pixel cells which are defined by a plurality of gate lines and data lines crossed horizontally and vertically. During the display process, a gate driving circuit can scan the gate lines progressively, and a data driving circuit can charge the pixel cells through the data lines.
In order to further reduce production cost of LCD products, the gate driving circuit in the prior art often adopts a design of Gate Driver on Array (GOA) to integrate a TFT (Thin Film Transistor) gate switching circuit on an array substrate of a display panel. This gate switching circuit integrated on the array substrate by using the GOA technique is also referred to as a GOA circuit or a shift register circuit.
In addition, Touch Screen Panel has also gradually pervaded people's lives. According to composition, the Touch Screen Panel can be divided into: Add on Touch Panel and In Cell Touch Panel. Compared to the Add on Touch Panel, the In Cell Touch Panel refers to integrating a touch screen and a display screen as an entirety, thus it has advantages of being light, thin and low lost.
Typically, the In Cell Touch Panel implements detection of a finger touch position by using the mutual capacitance or self-capacitance principle. Specifically, a mutual capacitive display panel is provided with mutual capacitors composed by touch driving lines (Tx lines) and touch sensing lines (Rx lines) perpendicular to each other. During the touch process, the human body electric field acts on the mutual capacitors, so that capacitance values of the mutual capacitors change. As for acquisition of touch signals in particular, each driving line may be scanned in sequence, then it is measured whether a capacitance value of a mutual capacitor at a certain point where a sensing line is crossed with this driving line changes, so as to obtain an exact contact position.
For known touch display devices, there are mutual interference when the gate lines and the touch driving lines (Tx lines) located in the same row are scanned simultaneously, so scanning of the gate lines and scanning of the touch driving lines (Tx lines) usually are performed in a time-sharing manner. However, as resolutions of display devices continue to increase, the blanking time will be compressed, which results in a reduction in scanning time of the touch driving lines (Tx lines), so that response time of touch signals is not enough, thereby responsiveness speed and sensitivity of Touch Screen Panels are reduced. If the blanking time is prolonged to ensure the response time of touch signals, a voltage at a gate of a driving transistor in the GOA circuit will be leaked by a transistor connected to said gate, thereby the gate scanning signal outputted by the GOA circuit is reduced, which results in insufficient charging of pixel cells, and dark line insufficiency or bright line insufficiency.